Go player Lee Sedol, seated right, reviews the game after losing to AlphaGo.
Photograph: Lee Jin-man/AP

Google’s AlphaGo computer program has won a third and decisive encounter with a top-ranked player of the Chinese board game Go in a victory marking significant developments in artificial intelligence.

Lee Sedol, who is the world’s second best player of the strategy game, lost three games in a row in Seoul this week, with the latest AlphaGo victory on Saturday handing Google the best-of-five match.

“I’ve never played a game where I felt this amount of pressure, and I wasn’t able to overcome this pressure,” Lee said at a post-game press conference.

Go has simple rules, but is highly intuitive and complex in practice. Mastering it has been an exceptionally difficult task for even the world’s best IT designers.

“We came here to challenge Lee, to learn from him and see what AG was capable of,” said Demis Hassabis, co-founder of Google’s artificial intelligence business, DeepMind, which created the program.

“AlphaGo controlled the momentum over more than four hours of gameplay, with Lee struggling to maintain territory against the program’s creative approach. Google DeepMind taught AlphaGo to recognise the optimal move in thousands of possible scenarios.”

AlphaGo’s dominance amounts to a significant, and much faster than previously expected, advance in artificial intelligence.

Google co-founder Sergey Brin, who was in Seoul to watch the third match, described Go as a beautiful game and said he was excited the company had been able to “instil that kind of beauty in our computers”.

Michael Redmond, one of the match’s commentators and a professional Go player, said some people initially doubted AlphaGo’s abilities. “After three matches and three straight victories, we are convinced,” he said.

AlphaGo won $1m in prize money, which Google DeepMind said would be donated to charities, including Unicef and Go organisations.

“AlphaGo controlled the game amazingly,” said Fan Hui, the European Go champion who was the first professional player to lose to the program when he played it in October.

Hui said the advances in artificial intelligence appeared to bode well for the future of the ancient game.

“We now have this new way of learning about Go. And look how many people are watching this now. More and more people are interested in Go now.”